Device for producing signals at predetermined intervals



Nov. 3, 1953 M. E. SNODDY DEVICE FOR PRODUCING SIGNALS AT PREDETERMINED INTERVALS Filed Jan. 30, 1952 2 Sheets-Sheet 1 MAX 5 Sm INVENTOR.

ATTORNEY Nov. 3, 1953 M. E. SNODDY 2,657,748

DEVICE FOR PRODUCING SIGNALS AT PREDETERMINED INTERVALS Filed Jan. 30, 1952 2 Sheets-Sheea 2 ATTORNEY Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE Max E. Snoddy, Dallas, Tex.

A p icati n January 95 eria N 269,079

13 Claims. l

This invention relates to a time contrpl device and mo e par cula l to a ime contro device for producing a signal of relatively short duration at a predetermined time.

In many applications, such as in apparatus for the irrigation of lawns, it is necessary that a signal of split second duration be transmitted to the apparatus at a particular time of the day to initiate its operation. A device for producing such a signal should he of simple construction, accurate in operation, and easy to set.

Acc r in l i s an o j of the vent n to provide a new and improved device for provide ing a signal of short duration at a predetermined time.

It is another object of the invention to provide a n and m ed lock ope a ed d ice for providing a signal at a predetermined time of the day.

It is still another object of the invention to pro.- vi a new and impr ved c ntr l dev e f s mp ru ged co ion o producin a signal at a predetermined time.

' Briefly stated, the new. and im roved device r p oduc n a s gnal at a p d te m ned ime e am n n d t ma n ai s t e lever a m I of a ro-swit h i nope a ive position until sh y e o e t ip arm diseneages from the cam to release it for movement to its old position, Th b dg s held y e lever arm after the cam m n s to mo e ac o ts orig nal po tion to ermit the lever arm to move to c uatin p s i n in w ch t micro svvi ch is. lo ed f r a s ort peri d of time th am a cining the le e am back to on-actua i g as i tates back to its o d position h i gea ed o the. cam to retard the speed of rotation of the cam to its old position.

For a better understanding of the inventio reference may be had to the following deserip: tion taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

In the drawing,

Figure 1 is a front plan view of the control device;

Figure 2 is a vertical sectional view taken on the line 22 of Figure 1;

Figure 3 is a front plan view showing the gradnations on the dial;

Figure 4 is a sectional view taken on line 4--4 ci'Fi iir-e 1;

Figure ,5 is an enlarged fragmentary plan view showing the cam, the toggle and the lever arm in two different operative positions; and

Figure 6 is a perspective View showing the cam, the toggle and a portion of the lever arm in their normal or rest positions.

Referring now to the drawing, a conventional electric clock motor 10 provided with the usual speed reducing gear train H is mounted on a supporting plate l2 by means of a spacing block 53 and screws 14. The drive shaft is driven by the motor and gear train extends into a. bore 16 in a main shaft IT. The frictional engagement of the drive shaft and the walls of the bore cause the main shaft to rotate with the drive shaft.

The main shaft I1 is journaled in a bearing sleeve I3 which has a reduced threaded portion I9 and an annular shoulder 20. The annular shoulder abuts the front side of the supporting plate 12 and the reduced threaded portion extends through an aperture in the supporting plate and is held in position by a washer 2'! which bears against the rear side of the supporting plate and a nut 22 threaded on the threaded portion.

A dial 23 is fastened onto a knob 24 whi h is rigidly secured on the outer end of the main shaft 11 by a set screw 25. The dial is prevented from slipping on the knob by a pin 24a which extends through the dial into the knob. The dial may be marked off in 24 divisions indicating the twenty-four hours of the day or it may be marked off into 48 divisions to indicate forty-eight hours if the gear train H is such as to cause the dial to complete a revolution once every two days.

A sleeve 26 is rotatably mounted on the main shaft between the dial 23 and the outer end of the hearing sleeve and has a reduced portion 21 forming an annular shoulder 28. A trip arm 29 is mounted on the rotatable sleeve 26 and its lower end bears against the annular shoulder 28. The outer end 2-9 of the trip arm is bent over the outer edge of the dial and is cut away to produce a pointer 30. A screw 3| extends through an. aperture in the bent outer end 29 into a threaded aperture in the trip arm to clamp the trip arm at any desired position on the dial. The trip arm rotates with the dial.

A portion of the trip arm is bent back, as at 32, to form a leg 33 which extends rearwardly toward the supporting plate l2 to engage the radially extending surface 34 of a cam 35. The cam 35 is rigidly mounted on a sleeve 38 which is rotatably mounted on the supporting plate I 2. The sleeve is rotatably mounted on a post 39 which has a reduced threaded portion 40 which extends through an aperture in the supporting plate and d is held therein by a washer ti and a nut it. The post 39 has an outer annular flange #33 so that the sleeve 38 is held between the flange ts and the front side of the supporting plate.

The cam is biased toward the position shown in Figure 1 by a spring M disposed about the sleeve 38 and having one end #15 rigidly secured to the sleeve and the other to post threaded in an aperture in the supporting plate. The post 36 extends outwardly to limit the movement of the cam in a clockwise direction, Figure 1, since the surface 34 of the cam will engage it.

The sleeve 38 is also provided with a pair of flanges 47 and at between which is received the arcuately cut-away inner end of the bridge 49. The bridge has two legs and which extend on opposite sides of the sleeve. The bridge is pivotable about the sleeve.

The cam 35 is provided with an arcuate slot 52 through which extends a screw 53. The screw 3 is threaded in a tapped aperture in the bridge and extends therethrcugh so that one end of a biasing spring may be secured thereto. The other end of the sprin is secured to a screw 55 threaded in a suitable aperture in the supporting plate It. The spring 56 biases the bridge in a clockwise direction, Figure 1..

The outer arcuate peripheral surface 56 of the bridge extends from a point where it is flush with the outer peripheral arcuate surface 5? of the cam to a point where it extends beyond it as at 58 when both bridge and cam are in their normal rest positions. The cam is cut-away at its periphery to provide a recess 559 having a sub stantially arcuate surface (it from which an inclined surface 6! extends to the arcuate peripheral surface 51.

The bent end 62 of the lever arm 55 of a microswitch 64 contacts the bridge and the cam and is actuated thereby to close or open the micro switch for a very short period of time. The micro-switch is secured to the supporting piate I2 by screws 55.

In use, the trip arm 29 is clamped on the dial at any desired position by the screw, the pointer 30 indicating the time at which the micro-switch will be actuated. The clock Hi and gear train II are of the type which allow the driving shaft l5 to rotate freely in a clockwise direction, Figure 1, but not in the opposite direction. The dial, therefore, can be rotated to set it in proper posi tion with respect to the actual time of the day. The cam 35 and bridge 48 are now in the positions shown in Figure 1 in which the spring 44 biases the cam 35 toward the post ili which limits its clockwise movement. The bridge is also biased in a clockwise direction by the spring 56 but its movement is limited by the abutment of the screw with the lower end of the slot 52 in the cam. The bent end 62 of the lever arm 63 abuts the outer peripheral surfaces 5 5 of the cam and bridge and is biased against them since the conventional micro-switch provides a spring bias.

As the clock motor rotates, the rive shaft l5 and the dial are rotated in a clockwise direction and the leg 33 of the trip arm finally contacts the radially extending surface of the cam. Fur ther continuous rotation. of the dial causes the trip arm to rotate the cam in a counterclockwise direction against the resistance of the spring 14 and 5 The bridge is also caused to rotate or pivot in a counter-clockwise direction since the lower edge of the slot 5'22 contacts the screw During this counter-clockwise movement, the

g bent arm 62 rides first on both peripheral surfaces 5! and and then, as the recess 53 portion of the cam rotates past the bent end, only on the peripheral surface of the bridge.

Eventually, the cam and recess are rotated to the full line position shown in Figure 5 in which the bent end (52 has ridden off the peripheral surface of the bridge and now rests on the peripheral surface 66 of the cam on the opposite side of the recess from the peripheral. surface The radius of the peripheral surface :56 is slightly less than the radius of the peripheral surfaces 55 and 51.

Further rotation of the dial causes the leg 33 of the trip arm to ride past and disengage from the radially extending surface 34 of the cam, freeing the cam to return to its original position. As the cam rotates back in a clockwise direction, the bent end 52 engages the notched side 61 of the bridge and prevents it from also rotating in a clockwise direction. The bent end 52 moves inward and rides on the arcuate surface 5'50 of the recess. When the bent end 5 of the lever arm 63 is in this extreme position, the micro-switch is closed or opened as the case may be and a signal is thus created. As the cam continues to rotate in a clockwise direction, the inclined surface 6! engages the bent arm and moves the bent arm outwardly until it is finally moved outwardly of the peripheral surface 56 of the bridge and out of engagement with the notched side 61 of the bridge. The bridge then moves in a clockwise direction back to the position shown in Figure 1. The cycle of operation is then repeated the next day to again make a signal at the pre determined time. It will be apparent that the micro-switch is connected in some control circuit so that when it is opened or closed, as the case may be, the control circuit causes some event to take place.

In order that the lever arm have sufficient time to move inwardly into the recess 59, the clockwise movement of the cam is retarded by a wheel 68 having a pinion gear 69 which meshes with the teeth 10 on the cam. The wheel 68 is rotatably mounted on the supporting panel by a post ll having a reduced end 12 threaded in a tapped hole in the supporting plate I2. The inertia of the wheel 68 slows down the movement of the cam so that the lever arm of the microswitch has sufiicient time to move to actuated position before the recess 59 moves past the bent end 52 of the lever arm.

It will be apparent now that even though the dial rotates very slowly, the coaction of the cam and toggle enable the micro-switch to be actuated for a very short period of time to make a signal of very short duration. Moreover, it will be seen that the time control device can be easily set to produce the signal at any predetermined time of the day and that it is or simple rugged construction.

While a preferred embodiment of the invention has been illustrated and described, it will be apparent that various changes and modifications can be made without departing from the invention, and it is intended, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In a device of the type described, a dial; means for rotating said dial at a constant speed, a trip arm adjustably secured to said dial for rotation therewith; a cam rotatably mounted for movement about an axis; abridge mounted for movement about said axis, said camand said bridge being connected for simultaneous movement in one direction; means biasing said ca ii and. said bridge in the. opposite direction; a switch having an operating lever normally held in inoperative position by said cam and said bridge, said trip arm engaging and rotating saidcam a predetermined distance in said one direction. as said dial is rotated, said cam having a recess, said bridge causing said lever to ride over saidv recess as said cam. is rotated in said v one direction, said recess allowing, said lever to move to actuated position as said cam rotates back in said opposite direction, said lever when in said actuated position preventing movement of said bridge in said opposite direction, said. recess.

ment in one direction; means biasing said cam.

and said bridge in the opposite direction; a

switch having an operating lever normally held in inoperative position by said cam and said bridge, said trip arm engaging and rotating said cam a predetermined distance inv said. one direction as said dial is rotated, said cam having a recess, said bridge causing said lever to ride over said recess as said cam is rotated in said one direction, said recess allowing said lever to move to actuated position as said cam rotates back in said opposite direction, said lever when in said actuated position preventing movement of said bridge in said opposite direction, said recess having a camming surface to move said lever back to non-actuated position as said cam rotates in said opposite direction; and means for retarding the movement of said cam in said opposite direction.

3. A time control device for actuating a switch having a lever comprising, an operating cam and a bridge mounted in side by side relation for independent rotatable movement about a common axis, said cam and said bridge having arcuate peripheral surfaces, the peripheral surface of said bridge extending arcuately outwardly beyond the arcuate peripheral surface of said cam, said cam having a recess providing a camming surface a portion of which is disposed inwardly of said arcuate peripheral surfaces; means biasing said cam and bridge in one direction, said cam and bridge being connected. for simultaneous movement in the opposite direction; and. means for rotating said cam a predetermined distance in said opposite direction, said lever riding over said peripheral surface of said bridge as said cam rotates in said opposite direction, said lever moving into said recess and into actuated pcsi tion as said cam is released for movement in said opposite direction and preventing movement of said bridge in said opposite direction, said cam-- ming surface of said recess moving said. lever out of actuated position and out of said recess as said.

cam moves in said opposite direction to free said bridge for movement in said opposite direction.

4. A time control device for actuating a switch having a lever comprising, an operating cam and a bridge mounted in side by side relation for iii) independent rotatable movement about a. common. axis, said cam and said bridge: having arcuate peripheral surfaces, the peripheral surface of said bridge extending arcuate outwardly beyond the arcuate peripheral surface of said cam, said cam having a recess providing a camming surface a portion of which is disposed inwardly ofv said arcuate peripheral surfaces; means biasing said cam and bridge in one direction, said cam and bridge being connected for simultaneous movement in the opposite direction; means for rotating said cam a predetermined distance insaid opposite direction, said lever riding over said peripheral surface of said bridge as said cam rotates in said opposite direction, said lever moving into said recess and into actuated position as said cam is released for movement in said opposite direction and preventing movement of said bridge in said opposite direction, Said camming surface of said recess moving said lever out of actuated position and out of said recess as said cam moves in said opposite direction to. free said bridge for movement in said opposite direction; and means for retarding the movement of said cam in said opposite direction.

5. The device of claim 3 characterized in that said means for moving said cam in said opposite direction comprises a rotatable dial, a trip arm ad-justably secured on said dial, said trip armengaging said cam to move it a predetermined distance in said opposite direction as said dial is rotated.

6. A time control device for actuating a switch having an operatin lever comprising, a cam and a bridge mounted in side by side relation for independent rotatable movement about a common axis, said cam and said bridge having arcuate peripheral surfaces, the peripheral surface of said bridge. extending arcuately outwardly beyond the arcuate peripheral surface of said cam, said cam having a recess providing a camming surface a portion of which is disposed inwardly of said arcuate peripheral surfaces; means biasing said cam and bridge in one direction, said cam having an arcuate slot; means on said bridge extending through said slot whereby said bridge is moved by said cam in the opposite direction when said cam is moved in said opposite direction; and means for rotating said cam a predetermined distance in said opposite direction, said lever riding over said peripheral surface of said bridge as said cam rotates in said opposite direction, said lever moving into said recess and into actuated position as said cam is releasedfor movement in said opposite direction and preventing movement of said bridge in said opposite direction, said camming surface. of saidrecess moving said lever out of actuated position and out of said recess as said cam moves in said opposite direction to free said bridge for movement in said opposite direction.

7. A time control devicev for actuating a switch having an operating lever comprising, a cam and a bridge mounted in side by side relation for independent rotatable movement about a common axis, said cam and said bridge having arcuate peripheral surfaces, the peripheral surface of said bridge extending arcuately outwardly beyond the arcuate peripheral surface of said cam, said cam having a recess providing a camming. surface a portion of which is disposed inwardly ofsaid arcuate peripheral surfaces; means biasing said cam and bridge in one. direction, said cam having an arcuate slot; means on said bridge xtending through said slot whereby said bridge.

,1 is moved by said cam in the opposite direction when said cam is moved in said opposite direction; means for rotating said cam a predetermined distance in said opposite direction, said lever riding over said peripheral surface of said bridge as said cam rotates in said opposite direction, said lever moving into said recess and into actuated position as said cam is released for movement in said opposite direction and preventing movement of said bridge in said opposite direction, said camming surface of said recess moving said lever out of actuated position and out of said recess as said cam moves in said opposite direction to free said bridge for movement in said opposite direction; and means for retarding the movement of said cam in said one direction.

8. The device of claim 6 characterized in the said means for moving said cam in said opposite direction comprises a rotatable dial, a trip arm adiustably secured on said dial, said trip arm engaging said cam to move it a predetermined distance in said opposite direction as said dial is rotated.

9. In a device of the type described, a dial; means for rotating said dial at a constant speed, a trip arm adiustably secured to said dial for rotation therewith; a cam rotatabiy mounted for movement about an axis; a bridge mounted for movement about said axis; said cam having a slot; means on said bridge extending into said slot whereby said bridge is moved by said cam in one direction when said cam. is moved in one direction; means biasing said cam and said bridge in the opposite direction; a switch having an operating lever normally held in inoperative position by said cam and said bridge, said trip arm engaging and rotating said cam a predetermined distance in said one direction as said dial is rotated, said cam having a recess, said bridge causing said lever to ride over said recess as said cam is rotated in said one direction, said recess allowing said lever to move to actuated position as said cam rotates back in said opposite direction, said lever when in said actuated position preventing movement of said bridge in said opposite position, said recess having a camming surface to move said lever back to nonactuated position as said cam rotates in said opposite direction.

10. In a device of the type described, a dial; means for rotating said dial at a constant speed, a trip arm adjustably secured to said dial for rotation therewith; a cam rotatably mounted for movement about an axis; a bridge mounted for movement about said axis; said cam having a slot, means on said bridge extending into said slot whereby said bridge is moved by said cam in one direction when said cam is moved in said one direction; means biasing said cam and said bridge in the opposite direction; a switch having an operating lever normally held in inoperative position by said cam and said bridge, said trip arm engaging and rotating said cam a predetermined distance in said one direction as said dial is rotated, said cam having a recess, said bridge causing said lever to ride over said recess as said cam is rotated in said one direc tion, said recess allowing said lever to move to actuated position as said cam rotates back in said opposite direction, said lever when in said actuated position preventing movement of said bridge in said opposite position, said recess having a camming surface to move said lever back it to non-actuated position as said cam rotates in said opposite direction; and means for retarding movement of said cam in said opposite direction.

11. In a device of the type described, a dial; means for rotating said dial at a constant speed, a trip arm adjustably secured to said dial for rotation therewith; a cam rotatably mounted for movement about an axis; a bridge mounted for movement about said axis, said cam having a slot; means on said bridge extending into said slot whereby said bridge is moved by said cam in one direction when said cam is moved in said one direction; means biasing said cam and said bridge in the opposite direction; a switch having an operating lever normally held in inoperative position by said cam and said bridge, said trip arm engaging and rotating said cam a predetermined distance in said one direction as said dial is rotated, said cam having a recess, said bridge causing said lever to ride over said recess as said cam is rotated in said one direction, said recess allowing said lever to move to actuated position as said cam rotatesback in said opposite direction, said lever when in said actuated position preventing movement of said bridge in said opposite position, said recess having a camming surface to move said lever back to nonactuated position as said cam rotates in said opposite direction; gear teeth on said cam; and a pinion gear on a weighted wheel meshing with said gear teeth whereby the inertia of said wheel retards the movement of said cam in said 0D-. posite direction.

12. in a device of the type described, a dial; means for rotating said dial at a constant speed, trip arm adjustably secured to said dial for rotation therewith; a cam rotatably mounted for movement about an axis; a bridge mounted for movement about said axis, said cam and said bridge being connected for simultaneous movement in one direction; means biasing said cam and said bridge in the opposite direction; a switch having an operating lever normally held in inoperative position by said cam and said bridge, said trip arm engaging and rotating said cam a predetermined distance in said one direction as said dial is rotated, said cam having a recess, said bridge causing said lever to ride over said recess as said cam is rotated in said one direction, recess allowing said lever to move to actuated position as said cam rotates back in said opposite direction, said lever when in said actuated position preventing movement of said bridge in said opposite position, said recess having a camming surface to move said lever back to non-actuated position as said cam rotates in said opposite direction; gear teeth on said cam; and a pinion gear on a weighted wheel meshing with said gear teeth whereby the inertia of said wheel retards the movement of said cam in said opposite direction.

13. A time control device for actuating a switch having an operating lever comprising a cam and a bridge mounted in side by side relationship for independent rotatable movement about a common axis, said cam and bridge being connected for simultaneous movement in one direction about said axis; means biasing said cam and said bridge in the opposite direction, said operating lever being normally held in inoperative position by said cam and said bridge; means for rotating said cam a predetermined distance in said one direction, said cam having a recess, said bridge causing said lever to ride over said MAX E. SNODDY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Porter Nov. 10, 1931 Brown et a1 Dec. 10, 1940 Aitken Nov. 15, 1949 Sisson Apr. 1'? ,1951 Clemens May 22, 1951 Schellens Jan. 15, 1952 Rasini Feb. 12, 1952 Beiser Feb. 26, 1952 

